OPK and Ovulation

[Pink10]

I did a digital OPK yesterday at 1pm which was neg. It was positive at 6pm (yesterday) and positive again at 9pm today. Does that mean I have not yet ovulated? Does OPK have to go back to negative to be sure that ovulation has happened?

[Dreamofpink]

Opk's don't actually 'record' ovulation, for want of a better word. They tell you when your LH surge has taken place, which is a hormone that triggers ovulation. Usually you'll ovulate around 12-48 hours after a positive OPK, but the surge can be quite short or last a day or so depending on the lady. The only thing that you can do to ensure that ovulation has taken place (apart from going for medical confirmation) is to track you body basal temperature. There are plenty of ladies who can advise you on that if you're interested. Hope that helps you and welcome to the site! :bigsmile:

[LacePrincess]

This graph pretty much shows you everything you need to know about how the hormones evolve in your cycle:

http://www.clearblue-fertility-monitor.net/clearblue-fertility-monitor-hormone-graph.jpg

OPK's detect the peak of that LH surge - which *should* cause the egg to burst out of the follicle. (I say 'should' because there is such thing as a false LH surge where you produce LH but it doesn't result in a successful egg.) The egg pops anywhere from 12-48 hours after your first +OPK. It's irrelevant how long the LH surge lasts - it differs from woman to woman and can also change month to month in the SAME woman. So some ladies will get one +OPK, and some will get multiple days of +OPK, but it doesn't matter because only the FIRST +OPK counts.

There is no way of knowing how long after your +OPK your egg will pop, unless you're married to an OBGYN and have an u/s at your convenient disposal. ;)

The only way to tell if you've successfully ovulated is to chart your BBT - a sustained thermal shift of 3 days will confirm that ovulation has passed.

So in your case, your first +OPK was yesterday at 6pm, that is when you start counting down the 12-48 hours. You should be o'ing today or tomorrow. :)

[Pink10]

Thank you for this, It's so hard to work out O+12. I'm hoping O day turns out to be yesterday CD17 which would mean we did 1 day cut off and day after O if we BD tonight! OPK was negative first thing this morning (7am).
Here's my chart:

http://www.fertilityfriend.com/home/38ddc8//thumb.png
My Ovulation Chart (http://www.fertilityfriend.com/home/38ddc8/) || Ovulation Tracker (http;//www.fertilityfriend.com)

[LacePrincess]

Looks like you should be o'ing today. :) You'll know if you see your temp go up tomorrow.

Don't even bother with O+12. You really don't have ANY way of telling when you actually O, it's impossible unless you get very precise O pain. The vast majority of pregnancies are from the two days before O. Even bd'ing on O day itself is a low chance of pregnancy, and O+1 is pretty much useless as well. FF advises O+1 only because sometimes you might O later than your chart indicates.

[atomic sagebrush]

If you MUST do O+12, an easy way without all the confusion is just to BD 48 hours after first pos OPK. YOu may be too late to catch the egg, but you won't be early!!!